Seismic reflection characteristics of fluvial sand and shale interbedded layers

Abstract

A sedimentary geological model is established in order to study the seismic refl ection characteristics of channel sand bodies. Synthetic seismic shot gathers are simulated using the acoustic wave equation and then are prestack time migrated. On the imaged data, the refl ection characteristics and instantaneous attributes are analyzed and log-constrained impedance inversion is tested. Because of wave fi eld interference, the experimental results show that seismic events do not defi nitely correspond to the channel sand bodies and that seismic modes of occurrence do not represent the actual ones. The seismic events formed by wave interference may lead to errors and pitfalls in sand body interpretation. The corresponding relations between instantaneous seismic attributes and sedimentary sands are not well established. Log-constrained impedance inversion improves the resolution of channel sands. However, if the inverted resolution is forced to be too high, artifacts related to the initial model may occur.

Potential risks of spectrum whitening deconvolution — Compared with well-driven deconvolution

“…Assuming that the spectrum of a refl ectivity series is approximately white, adjusting the amplitude spectrum of seismic record is equivalent to adjusting that of the wavelet (Li et al, 2008).…”